The present invention relates to a ring-like, radial, shaft-sealing element.
With on known radial shaft-sealing element (U.S. Pat. No. 2,736,585), a sealing member, embodied as a molded member, is placed in a recessed portion of a spring member. The sealing member covers half of the axial width of the end portion of the spring member. Since in the installed state the sealing member rests against the shaft that is to be sealed under prestress, the sealing member is heated up during operation. Furthermore, since the sealing member is partially embedded in the spring member, which is made of elastomeric material, the heat that is generated during operation cannot be dissipated to a sufficient extent by the sealing member. For this reason, the sealing member is subjected to increased wear.
Radial shaft-sealing elements are also known (U.S. Pat. No. 2,804,325) where the spring member, which is made of flexible material, is embodied as a sealing flange, the free end of which is provided with a sealing lip. The sealing portion is embodied as a foil of polytetrafluoroethylene, and is secured to the sealing lip. The sealing portion extends all the way to the support member, to which it is secured. The sealing part or member thus shields the spring member over the entire axial length, and over the entire periphery, relative to the shaft that is to be sealed off. Since the sealing member is made of polytetrafluoroethylene, it has a relatively great rigidity, which is an advantage for the sealing function. However, in the region between the sealing region that rests against the shaft and the support member, the sealing member is not very flexible due to this rigidity. If the shaft, due to some eccentricity, experiences a radial movement or wobble, the sealing member cannot absorb such a movement to a sufficient extent. The stresses that result due to the radial movement or wobble are transmitted along to the sealing surface via that portion of the sealing member that is disposed between the support member and the actual sealing region. As a result, a deformation of the sealing member occurs in the sealing region, thus considerably reducing the sealing capacity.
It is an object of the present invention to embody a radial shaft-sealing element in such a way that while retaining the sealing contact of the sealing member, even during radial movement or wobble of the shaft, the heat that is generated during operation in the sealing member can be rapidly dissipated, so that the sealing member is stressed only slightly.